Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare destructiveHint=true and readOnlyHint=false, so the destructive nature is covered. The description adds useful behavioral context by clarifying that the operation applies across multiple files and supports both plain text and regular expressions, which goes beyond what the annotations alone convey.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences, both purposeful, with the primary use case front-loaded and exclusions clearly stated. No filler or redundant restatement of the tool name or schema.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a destructive multi-file operation with a rich input schema, an output schema, and safety annotations, the description covers the core decision the agent needs: when to pick this tool over its siblings. Nothing essential for correct invocation is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the schema fully documents all 8 parameters including regex, dry_run, and maxFiles. The description provides high-level context but no additional parameter-level semantics beyond what the schema already supplies, so a baseline 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states a specific operation: search and apply a text or regex replacement across multiple files under a path, with concrete examples like rename or version bump. It also distinguishes itself from siblings by naming edit_block and write_file as alternatives.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description opens with 'Use this when...' and gives explicit conditions for use: same replacement across multiple files. It also states when not to use it: one known block should use edit_block, and one complete known file should use write_file.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.